this is really going to impact the eastern half of the united states. >> leigh, residents on the eastern seaboard are already bracing for the storm's impact. millions are being warned to get somewhere safe and to stay put. reporter: images that speak for themselves. hurricane sandy has that yet made landfall in the u.s. but its fierce winds and rain still are making travel difficult in ocean city, maryland. maryland has already declared a state of emergency. after being briefed by federal officials on the movement of the storm, president obama had this to say -- my main message to everybody involved, we have to take this seriously. my message to the governors and the mayors is, anything they need, we will be there. >> many or heeding the warnings, from north carolina to maine. >> i don't know what to expect at this point. we had irene here, had winds of 80 miles-per-hour sustained, and that was -- >> forecasters fear sandy could u-merge with the cold front, bringing up to a foot of rain in parts. heavy snow could also be possible in the appalachian mountain region, public transportation